1. Field of the Invention
This invention relates to a skate wheel and more particularly to a pre-pressurized pneumatic in-line skate wheel of integral construction and having an internal integral bladder device comprising a tube and lobe structure in fluid communication and chamber structure in fluid communication.
2. Description of the Prior Art
In the recent past, roller skate design has developed into a growth industry. High technology performance wheels and skate designs have drastically altered the concepts and designs that have previously been in vogue. In turn, these design alterations have created a demand for enhanced performance and more technologically advanced skates for all types of users. No longer are recreational skaters content with a basic skate having basic wheels, today even those who are infrequent skaters find themselves expecting better performance, and lighter weight skates with more durable skate wheels. The present invention will satisfy these needs.
Roller skates have been known in the art for over a century. Early roller skates were designed in various forms, the most common of these included four wheels placed in a box-like configuration. This design made it easy for the skater to balance but did not afford the high level of precision and maneuverability desired by many skaters. Typically, most wheels used in early roller skates were manufactured from metal or wood. Such a wheel would facilitate movement but at the cost of comfort. In an attempt to improve the cushioning properties of the skate, while at the same time providing a resilient tire, it was proposed to design a partially pneumatic and partially solid tire comprised of multiple components with varying resiliencies. A wheel of this type was disclosed in U.S. Pat. No. 1,244,209 to Hickman. Such a wheel enhanced the skater comfort but could easily break down due to the multi-component structure.
Precision and maneuverability soon became to most desired traits for the recreational skater and it was thereafter proposed to mount the wheels in tandem along the length of the skate. In this way, the roller skater could enjoy the precision and performance normally associated with ice skates yet have the freedom and use available with outdoor skates. By creating a tandem roller skate, with "in-line" wheel placement, the user was able to make quick starts, sudden stops, and high speed turns. A device of this type was disclosed in U.S. Pat. No. 2,570,349 to Kardhordo. The wheels in Kardhordo were also made of rubber material to enhance the gripping properties and maneuverability.
This "in-line" skate style has become extremely popular for both recreational purposes and for the professional skater. The typical configuration of the modern in-line skate aligns four wheels, in tandem, along the length of the skate. Such an alignment allows the skater to travel with less friction and resistance, comparable to ice skating. When the recreational skater uses his in-line skates, he will typically traverse over a variety of surfaces. When skating over asphalt or concrete the skate may encounter gravel, loose rocks or cracks. It is thus important that the skate wheel be capable of absorbing shock and yet provide a smooth ride at a fast pace all without undue resistance to rolling under load.
Generally, modern skate wheels have been constructed using solid polyurethane mounted on a hub. Such wheels provide a relatively smooth ride but are limited in their ability to either provide wheels capable of high speeds, or which have enhanced shock absorption capabilities. A solid tire body is restricted in its ability to cushion and absorb shock associated with different loads applied to the tire when encountering irregular surfaces. Since a great portion of in-line skates are used in recreational skating involving various maneuvers over outdoor surfaces, it is important that they withstand numerous, different, side loads which result from inclinations of the skate as the rider travels over uneven ground, makes sharp turns, and jumps over small obstacles. Many skaters would like to have the option of skating one day at high speeds on relatively rigid wheels, and the next day on more resilient wheels which can accommodate relatively rough terrain. It is therefore apparent that the design of in-line skate wheels involves more and different factors than that involved in designing traditional roller skate wheels. As can be seen, the performance requirements for in-line skates are extremely high, even as dictated by the casual skater.
It is desirable that an in-line skate wheel be capable of withstanding numerous different loads, as well as being resilient to provide shock absorbent characteristics. This ability to absorb shock is most critical when traveling over rocks or other uneven surfaces. Failure of the wheel to provide for shock absorption may result in the rider incurring injury to his or her knees or legs as a result of constant vibration, or imposition of a sharp jolt. But, increased shock absorption in a solid urethane wheel, typically limits results in performance parameters important to high speed skating.
It was thereafter proposed to encapsulate an adjustable pneumatic tube within a polyurethane tire body and having a valve structure to adjust the pressure within the tube. Such a configuration enables the user to vary the performance requirement of the tire by adjusting the amount of air inside. Thus, a tire with more air will allow the rider to achieve high speeds since the tire is less resilient, while a tire with less air will be more resilient and more shock absorbent. Such a device was disclosed in U.S. Pat. No. 5,630,891 to Peterson, and the inventor of the present invention, and was assigned to the assignee of this application. However, such a wheel is expensive to manufacture and requires the user to physically adjust the tire depending on the changing surface characteristics.
It has been recently proposed to provide a pre-pressurized pneumatic in-line skate wheel having a tube and a plurality of bladders inside a polyurethane tire. This design combines the absorption afforded through a pneumatic tire while providing the resiliency and speed capabilities achievable through a harder polyurethane tire. I proposed such a construction in U.S. Pat. No. 5,461,365, assigned to the assignee of this application. Although such a structure generally achieves the desired objective, it is costly to manufacture and due to the discrete structure of the bladders the possibility of puncture and other damage to the bladder may easily render the wheel unusable, furthermore, such a structure required that the bladder be maintained at a high pressure.
In other areas of the art, such as in the construction of variable pressure athletic shoes, it has been known to provide elastomeric bladders configured with multiple discrete chamber, open cell elastomeric foam, having inlet and outlet valves. Devices of this type are shown in U.S. Pat. No. 4,287,250 to Rudy and U.S. Pat. No. 5,144,708 to Pekar. However, such bladders have not been generally adapted to, or employed in skate wheel construction.
Thus, there remains the need to provide an in-line skate wheel utilizing a low pressure polyurethane and pneumatic structure, which is configured in such a way as to provide shock absorption, high speed capabilities, and resiliency while maintaining a high degree of durability and still it be relatively inexpensive to manufacture. Thus, the rider may enjoy a comfortable and fast wheel which has a long life without forgoing any performance characteristics.